relays are common in marine, off-shore, and off-highway designs; food processing, communications, and plants that process petroleum products; power-station and substation control panels; office automation equipment (such as
With the load of new substation grow with each passing day,more and more,which has different manufacturer,different types of the main transformer protection.Due to the protection of the different models,differential protection on differential current calculation is put in certain difference,ratio differe...
Medium-voltage circuit breakers nearly always use separate current sensors and protective relays, instead of relying on built-in thermal or magnetic overcurrent sensors. Medium-voltage circuit breakers can also be classified by the medium used to extinguish the arc as Vacuum, SF6, Airblast, and oil...
The variations of the quantity being measured are recorded by a pen (attached to the moving system of the instrument ; the moving system is operated by the quantity being measured) on a sheet of paper carried by it rotating drum. For example, we may have a recording voltmeter in asubstati...
Online contact diagnostics can be performed after the unit is manufactured or while the unit is already operating in the substation. The overall condition of the switching apparatus, including its current paths and connecting terminals, is evaluated. The static method consists in injecting direct curre...